From 7aa1c8f47e7e792d11f898cbdddaf6fa21ff08cc Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 11 Oct 2012 18:14:58 +0200 Subject: [PATCH] MIPS: kdump: Add support [ralf@linux-mips.org: Original patch by Maxim Uvarov with plenty of further shining, polishing, debugging and testing by me.] Signed-off-by: Maxim Uvarov Cc: linux-mips@linux-mips.org Cc: kexec@lists.infradead.org Cc: horms@verge.net.au Patchwork: https://patchwork.linux-mips.org/patch/1025/ Signed-off-by: Ralf Baechle --- arch/mips/Kconfig | 23 ++++++++ arch/mips/include/asm/kexec.h | 27 ++++++++- arch/mips/include/asm/smp.h | 6 ++ arch/mips/kernel/Makefile | 3 +- arch/mips/kernel/crash.c | 71 ++++++++++++++++++++++++ arch/mips/kernel/crash_dump.c | 77 ++++++++++++++++++++++++++ arch/mips/kernel/machine_kexec.c | 33 +++++++++-- arch/mips/kernel/relocate_kernel.S | 88 +++++++++++++++++++++++++++++- arch/mips/kernel/setup.c | 56 +++++++++++++++++++ arch/mips/kernel/smp.c | 17 ++++++ arch/mips/kernel/traps.c | 4 ++ 11 files changed, 396 insertions(+), 9 deletions(-) create mode 100644 arch/mips/kernel/crash.c create mode 100644 arch/mips/kernel/crash_dump.c diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 462f9c4fe2e5..c97fc030fdac 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2379,6 +2379,29 @@ config KEXEC support. As of this writing the exact hardware interface is strongly in flux, so no good recommendation can be made. +config CRASH_DUMP + bool "Kernel crash dumps" + help + Generate crash dump after being started by kexec. + This should be normally only set in special crash dump kernels + which are loaded in the main kernel with kexec-tools into + a specially reserved region and then later executed after + a crash by kdump/kexec. The crash dump kernel must be compiled + to a memory address not used by the main kernel or firmware using + PHYSICAL_START. + +config PHYSICAL_START + hex "Physical address where the kernel is loaded" + default "0xffffffff84000000" if 64BIT + default "0x84000000" if 32BIT + depends on CRASH_DUMP + help + This gives the CKSEG0 or KSEG0 address where the kernel is loaded. + If you plan to use kernel for capturing the crash dump change + this value to start of the reserved region (the "X" value as + specified in the "crashkernel=YM@XM" command line boot parameter + passed to the panic-ed kernel). + config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" depends on PROC_FS diff --git a/arch/mips/include/asm/kexec.h b/arch/mips/include/asm/kexec.h index 4314892aaebb..ee25ebbf2a28 100644 --- a/arch/mips/include/asm/kexec.h +++ b/arch/mips/include/asm/kexec.h @@ -9,22 +9,43 @@ #ifndef _MIPS_KEXEC # define _MIPS_KEXEC +#include + /* Maximum physical address we can use pages from */ #define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000) /* Maximum address we can reach in physical address mode */ #define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000) /* Maximum address we can use for the control code buffer */ #define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000) - -#define KEXEC_CONTROL_PAGE_SIZE 4096 +/* Reserve 3*4096 bytes for board-specific info */ +#define KEXEC_CONTROL_PAGE_SIZE (4096 + 3*4096) /* The native architecture */ #define KEXEC_ARCH KEXEC_ARCH_MIPS +#define MAX_NOTE_BYTES 1024 static inline void crash_setup_regs(struct pt_regs *newregs, struct pt_regs *oldregs) { - /* Dummy implementation for now */ + if (oldregs) + memcpy(newregs, oldregs, sizeof(*newregs)); + else + prepare_frametrace(newregs); } +#ifdef CONFIG_KEXEC +struct kimage; +extern unsigned long kexec_args[4]; +extern int (*_machine_kexec_prepare)(struct kimage *); +extern void (*_machine_kexec_shutdown)(void); +extern void (*_machine_crash_shutdown)(struct pt_regs *regs); +extern void default_machine_crash_shutdown(struct pt_regs *regs); +#ifdef CONFIG_SMP +extern const unsigned char kexec_smp_wait[]; +extern unsigned long secondary_kexec_args[4]; +extern void (*relocated_kexec_smp_wait) (void *); +extern atomic_t kexec_ready_to_reboot; +#endif +#endif + #endif /* !_MIPS_KEXEC */ diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h index d4fb4d852a6d..f33b5fd6972b 100644 --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -40,6 +40,8 @@ extern int __cpu_logical_map[NR_CPUS]; #define SMP_CALL_FUNCTION 0x2 /* Octeon - Tell another core to flush its icache */ #define SMP_ICACHE_FLUSH 0x4 +/* Used by kexec crashdump to save all cpu's state */ +#define SMP_DUMP 0x8 extern volatile cpumask_t cpu_callin_map; @@ -91,4 +93,8 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) mp_ops->send_ipi_mask(mask, SMP_CALL_FUNCTION); } +#if defined(CONFIG_KEXEC) +extern void (*dump_ipi_function_ptr)(void *); +void dump_send_ipi(void (*dump_ipi_callback)(void *)); +#endif #endif /* __ASM_SMP_H */ diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 8b28bc4e14ea..764597b5fb56 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -80,7 +80,8 @@ obj-$(CONFIG_I8253) += i8253.o obj-$(CONFIG_GPIO_TXX9) += gpio_txx9.o -obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o crash.o +obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_SPINLOCK_TEST) += spinlock_test.o obj-$(CONFIG_MIPS_MACHINE) += mips_machine.o diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c new file mode 100644 index 000000000000..0f53c39324bb --- /dev/null +++ b/arch/mips/kernel/crash.c @@ -0,0 +1,71 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* This keeps a track of which one is crashing cpu. */ +static int crashing_cpu = -1; +static cpumask_t cpus_in_crash = CPU_MASK_NONE; + +#ifdef CONFIG_SMP +static void crash_shutdown_secondary(void *ignore) +{ + struct pt_regs *regs; + int cpu = smp_processor_id(); + + regs = task_pt_regs(current); + + if (!cpu_online(cpu)) + return; + + local_irq_disable(); + if (!cpu_isset(cpu, cpus_in_crash)) + crash_save_cpu(regs, cpu); + cpu_set(cpu, cpus_in_crash); + + while (!atomic_read(&kexec_ready_to_reboot)) + cpu_relax(); + relocated_kexec_smp_wait(NULL); + /* NOTREACHED */ +} + +static void crash_kexec_prepare_cpus(void) +{ + unsigned int msecs; + + unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ + + dump_send_ipi(crash_shutdown_secondary); + smp_wmb(); + + /* + * The crash CPU sends an IPI and wait for other CPUs to + * respond. Delay of at least 10 seconds. + */ + pr_emerg("Sending IPI to other cpus...\n"); + msecs = 10000; + while ((cpus_weight(cpus_in_crash) < ncpus) && (--msecs > 0)) { + cpu_relax(); + mdelay(1); + } +} + +#else /* !defined(CONFIG_SMP) */ +static void crash_kexec_prepare_cpus(void) {} +#endif /* !defined(CONFIG_SMP) */ + +void default_machine_crash_shutdown(struct pt_regs *regs) +{ + local_irq_disable(); + crashing_cpu = smp_processor_id(); + crash_save_cpu(regs, crashing_cpu); + crash_kexec_prepare_cpus(); + cpu_set(crashing_cpu, cpus_in_crash); +} diff --git a/arch/mips/kernel/crash_dump.c b/arch/mips/kernel/crash_dump.c new file mode 100644 index 000000000000..d9ec3898f9fa --- /dev/null +++ b/arch/mips/kernel/crash_dump.c @@ -0,0 +1,77 @@ +#include +#include +#include +#include + +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + +static int __init parse_savemaxmem(char *p) +{ + if (p) + saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1; + + return 1; +} +__setup("savemaxmem=", parse_savemaxmem); + + +static void *kdump_buf_page; + +/** + * copy_oldmem_page - copy one page from "oldmem" + * @pfn: page frame number to be copied + * @buf: target memory address for the copy; this can be in kernel address + * space or user address space (see @userbuf) + * @csize: number of bytes to copy + * @offset: offset in bytes into the page (based on pfn) to begin the copy + * @userbuf: if set, @buf is in user address space, use copy_to_user(), + * otherwise @buf is in kernel address space, use memcpy(). + * + * Copy a page from "oldmem". For this page, there is no pte mapped + * in the current kernel. + * + * Calling copy_to_user() in atomic context is not desirable. Hence first + * copying the data to a pre-allocated kernel page and then copying to user + * space in non-atomic context. + */ +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, + size_t csize, unsigned long offset, int userbuf) +{ + void *vaddr; + + if (!csize) + return 0; + + vaddr = kmap_atomic_pfn(pfn); + + if (!userbuf) { + memcpy(buf, (vaddr + offset), csize); + kunmap_atomic(vaddr); + } else { + if (!kdump_buf_page) { + pr_warning("Kdump: Kdump buffer page not allocated\n"); + + return -EFAULT; + } + copy_page(kdump_buf_page, vaddr); + kunmap_atomic(vaddr); + if (copy_to_user(buf, (kdump_buf_page + offset), csize)) + return -EFAULT; + } + + return csize; +} + +static int __init kdump_buf_page_init(void) +{ + int ret = 0; + + kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!kdump_buf_page) { + pr_warning("Kdump: Failed to allocate kdump buffer page\n"); + ret = -ENOMEM; + } + + return ret; +} +arch_initcall(kdump_buf_page_init); diff --git a/arch/mips/kernel/machine_kexec.c b/arch/mips/kernel/machine_kexec.c index 85beb9b0b2d0..992e18474da5 100644 --- a/arch/mips/kernel/machine_kexec.c +++ b/arch/mips/kernel/machine_kexec.c @@ -5,7 +5,7 @@ * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ - +#include #include #include #include @@ -19,9 +19,19 @@ extern const size_t relocate_new_kernel_size; extern unsigned long kexec_start_address; extern unsigned long kexec_indirection_page; +int (*_machine_kexec_prepare)(struct kimage *) = NULL; +void (*_machine_kexec_shutdown)(void) = NULL; +void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL; +#ifdef CONFIG_SMP +void (*relocated_kexec_smp_wait) (void *); +atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0); +#endif + int machine_kexec_prepare(struct kimage *kimage) { + if (_machine_kexec_prepare) + return _machine_kexec_prepare(kimage); return 0; } @@ -33,14 +43,20 @@ machine_kexec_cleanup(struct kimage *kimage) void machine_shutdown(void) { + if (_machine_kexec_shutdown) + _machine_kexec_shutdown(); } void machine_crash_shutdown(struct pt_regs *regs) { + if (_machine_crash_shutdown) + _machine_crash_shutdown(regs); + else + default_machine_crash_shutdown(regs); } -typedef void (*noretfun_t)(void) __attribute__((noreturn)); +typedef void (*noretfun_t)(void) __noreturn; void machine_kexec(struct kimage *image) @@ -52,7 +68,9 @@ machine_kexec(struct kimage *image) reboot_code_buffer = (unsigned long)page_address(image->control_code_page); - kexec_start_address = image->start; + kexec_start_address = + (unsigned long) phys_to_virt(image->start); + kexec_indirection_page = (unsigned long) phys_to_virt(image->head & PAGE_MASK); @@ -63,7 +81,7 @@ machine_kexec(struct kimage *image) * The generic kexec code builds a page list with physical * addresses. they are directly accessible through KSEG0 (or * CKSEG0 or XPHYS if on 64bit system), hence the - * pys_to_virt() call. + * phys_to_virt() call. */ for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE); ptr = (entry & IND_INDIRECTION) ? @@ -81,5 +99,12 @@ machine_kexec(struct kimage *image) printk("Will call new kernel at %08lx\n", image->start); printk("Bye ...\n"); __flush_cache_all(); +#ifdef CONFIG_SMP + /* All secondary cpus now may jump to kexec_wait cycle */ + relocated_kexec_smp_wait = reboot_code_buffer + + (void *)(kexec_smp_wait - relocate_new_kernel); + smp_wmb(); + atomic_set(&kexec_ready_to_reboot, 1); +#endif ((noretfun_t) reboot_code_buffer)(); } diff --git a/arch/mips/kernel/relocate_kernel.S b/arch/mips/kernel/relocate_kernel.S index 87481f916a61..0b108587f065 100644 --- a/arch/mips/kernel/relocate_kernel.S +++ b/arch/mips/kernel/relocate_kernel.S @@ -15,6 +15,11 @@ #include LEAF(relocate_new_kernel) + PTR_L a0, arg0 + PTR_L a1, arg1 + PTR_L a2, arg2 + PTR_L a3, arg3 + PTR_L s0, kexec_indirection_page PTR_L s1, kexec_start_address @@ -26,7 +31,6 @@ process_entry: and s3, s2, 0x1 beq s3, zero, 1f and s4, s2, ~0x1 /* store destination addr in s4 */ - move a0, s4 b process_entry 1: @@ -60,10 +64,92 @@ copy_word: b process_entry done: +#ifdef CONFIG_SMP + /* kexec_flag reset is signal to other CPUs what kernel + was moved to it's location. Note - we need relocated address + of kexec_flag. */ + + bal 1f + 1: move t1,ra; + PTR_LA t2,1b + PTR_LA t0,kexec_flag + PTR_SUB t0,t0,t2; + PTR_ADD t0,t1,t0; + LONG_S zero,(t0) +#endif + + sync /* jump to kexec_start_address */ j s1 END(relocate_new_kernel) +#ifdef CONFIG_SMP +/* + * Other CPUs should wait until code is relocated and + * then start at entry (?) point. + */ +LEAF(kexec_smp_wait) + PTR_L a0, s_arg0 + PTR_L a1, s_arg1 + PTR_L a2, s_arg2 + PTR_L a3, s_arg3 + PTR_L s1, kexec_start_address + + /* Non-relocated address works for args and kexec_start_address ( old + * kernel is not overwritten). But we need relocated address of + * kexec_flag. + */ + + bal 1f +1: move t1,ra; + PTR_LA t2,1b + PTR_LA t0,kexec_flag + PTR_SUB t0,t0,t2; + PTR_ADD t0,t1,t0; + +1: LONG_L s0, (t0) + bne s0, zero,1b + + sync + j s1 + END(kexec_smp_wait) +#endif + +#ifdef __mips64 + /* all PTR's must be aligned to 8 byte in 64-bit mode */ + .align 3 +#endif + +/* All parameters to new kernel are passed in registers a0-a3. + * kexec_args[0..3] are uses to prepare register values. + */ + +kexec_args: + EXPORT(kexec_args) +arg0: PTR 0x0 +arg1: PTR 0x0 +arg2: PTR 0x0 +arg3: PTR 0x0 + .size kexec_args,PTRSIZE*4 + +#ifdef CONFIG_SMP +/* + * Secondary CPUs may have different kernel parameters in + * their registers a0-a3. secondary_kexec_args[0..3] are used + * to prepare register values. + */ +secondary_kexec_args: + EXPORT(secondary_kexec_args) +s_arg0: PTR 0x0 +s_arg1: PTR 0x0 +s_arg2: PTR 0x0 +s_arg3: PTR 0x0 + .size secondary_kexec_args,PTRSIZE*4 +kexec_flag: + LONG 0x1 + +#endif + kexec_start_address: EXPORT(kexec_start_address) PTR 0x0 diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 290dc6a1d7a3..8c41187801ce 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -536,12 +537,64 @@ static void __init arch_mem_init(char **cmdline_p) } bootmem_init(); +#ifdef CONFIG_KEXEC + if (crashk_res.start != crashk_res.end) + reserve_bootmem(crashk_res.start, + crashk_res.end - crashk_res.start + 1, + BOOTMEM_DEFAULT); +#endif device_tree_init(); sparse_init(); plat_swiotlb_setup(); paging_init(); } +#ifdef CONFIG_KEXEC +static inline unsigned long long get_total_mem(void) +{ + unsigned long long total; + + total = max_pfn - min_low_pfn; + return total << PAGE_SHIFT; +} + +static void __init mips_parse_crashkernel(void) +{ + unsigned long long total_mem; + unsigned long long crash_size, crash_base; + int ret; + + total_mem = get_total_mem(); + ret = parse_crashkernel(boot_command_line, total_mem, + &crash_size, &crash_base); + if (ret != 0 || crash_size <= 0) + return; + + crashk_res.start = crash_base; + crashk_res.end = crash_base + crash_size - 1; +} + +static void __init request_crashkernel(struct resource *res) +{ + int ret; + + ret = request_resource(res, &crashk_res); + if (!ret) + pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n", + (unsigned long)((crashk_res.end - + crashk_res.start + 1) >> 20), + (unsigned long)(crashk_res.start >> 20)); +} +#else /* !defined(CONFIG_KEXEC) */ +static void __init mips_parse_crashkernel(void) +{ +} + +static void __init request_crashkernel(struct resource *res) +{ +} +#endif /* !defined(CONFIG_KEXEC) */ + static void __init resource_init(void) { int i; @@ -557,6 +610,8 @@ static void __init resource_init(void) /* * Request address space for all standard RAM. */ + mips_parse_crashkernel(); + for (i = 0; i < boot_mem_map.nr_map; i++) { struct resource *res; unsigned long start, end; @@ -593,6 +648,7 @@ static void __init resource_init(void) */ request_resource(res, &code_resource); request_resource(res, &data_resource); + request_crashkernel(res); } } diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 9005bf9fb859..2e6374a589ec 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -386,3 +386,20 @@ void flush_tlb_one(unsigned long vaddr) EXPORT_SYMBOL(flush_tlb_page); EXPORT_SYMBOL(flush_tlb_one); + +#if defined(CONFIG_KEXEC) +void (*dump_ipi_function_ptr)(void *) = NULL; +void dump_send_ipi(void (*dump_ipi_callback)(void *)) +{ + int i; + int cpu = smp_processor_id(); + + dump_ipi_function_ptr = dump_ipi_callback; + smp_mb(); + for_each_online_cpu(i) + if (i != cpu) + mp_ops->send_ipi_single(i, SMP_DUMP); + +} +EXPORT_SYMBOL(dump_send_ipi); +#endif diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 9be3df1fa8a4..da0c29422cf2 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -13,6 +13,7 @@ */ #include #include +#include #include #include #include @@ -409,6 +410,9 @@ void __noreturn die(const char *str, struct pt_regs *regs) panic("Fatal exception"); } + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + do_exit(sig); } -- GitLab